Genuine OEM Toyota Tensioner Assembly, part number 1662025021. This component is part of the engine's V-ribbed belt system. It functions to maintain the correct tension on the V-belt, ensuring all belt-driven accessories operate efficiently and without slippage. The assembly is designed for precise fitment within the engine bay. Genuine OEM tensioner assemblies are manufactured to exact specifications, guaranteeing consistent performance and longevity, crucial for maintaining the integrity of the accessory drive system.